Newegg is a good place to buy, same as Tiger. Even a local store may be competitive depending on the product.
I'd stick with the well known brands to start, such as Belkin, Dlink, Netgear, or Cisco. Make sure to get one that states it is an N compatible router b/g/n so you can use the speed your laptop's internal card is capable of.
After that, they are going to be very similar at the low end. Take a look at the features and find some that interest you and start there. All the routers will offer you a CD for easy installation and setup, so that shouldn't be an issue.